In what one officer dubbed the “biggest drug case of the year”, anti-drug police have confiscated more than 40 kilograms of drugs, including heroin and methamphetamine, from a pair of Chinese nationals in the capital’s Tuol Kork district.

The seizure, which took place over the course of two arrests – the first of which came on Thursday – included ecstasy pills, bottles of ketamine, heroin, methamphetamine and a yet-to-be tested substance that San Sothy, deputy director at the anti-drug department in the Interior Ministry, said is a likely precursor used in the manufacture of drugs.

“It is still not clear what the last substance is,” he said, confirming the nationality of the two suspects. “The suspects said the substance was used to produce ‘K’, which means ketamine.”

The duo sourced the drugs from Laos, and will be sent to court today, he added, refusing to divulge the names or additional details about the two individuals. “We have followed this case for five months. This is the biggest case we have for this year,” Sothy added.

Ngeng Chhuon, another deputy director at the anti-drug department, said police officials nabbed the first suspect outside a nightclub in Prampi Makara district on Thursday. That suspect then led them to a house in Tuol Kork, where they made the second arrest on the weekend.

“We have arrested the two people, but we are continuing [our investigation] into the provinces. We are now looking for the homeowner,” he said.

Meas Virith, secretary-general for National Authority for Combating Drugs (NACD), said he could not comment on the exact nature of the drugs as they had not been tested. He would only confirm that 40 kilograms of substances had been seized.

Also, the small bottles of ketamine that were confiscated, Virith said, looked like those used for medical purposes and had been purchased locally from markets.

Last week, the NACD reported a 70 percent increase in drug arrests from November 2015 to September 2016, as compared to the same period the previous year. These arrests netted 111 kilos of drugs, resulting in more than 3,400 drug cases sent to local courts.

Additional reporting by Ananth Baliga